I don't know anything about the actual differences between the vitamins directly from the fruit/veg and the pills, but I can think of a benefit of having the actual fruit/veg - you don't just get the particular vitamin, but you also get others (and minerals in some cases), as well as dietary fibres from the fresh fruit and veg.
As for me, I am having both fresh fruit/veg and vitamin pills - I'm popping Vitamin B, C, E, plus various others like Evening Primrose Oil, Aloe Vera etc.